1. Field of Invention
The present invention relates to a junction barrier Schottky (JBS) diode and a manufacturing method thereof; particularly, it relates to such JBS diode which includes an N-type gallium nitride (GaN) substrate and manufacturing method thereof.
2. Description of Related Art
FIG. 1 shows a schematic diagram of a prior art junction barrier Schottky (JBS) diode 100 from cross-section view. As shown in FIG. 1, the JBS diode 100 includes an N-type silicon substrate 11, a first N-type epitaxial silicon layer 12, a second N-type epitaxial silicon layer 13, a P-type grid 14, an anode conductive layer 15, and a cathode conductive layer 16. The N-type impurity concentration of the N-type silicon substrate 11 is about 1E19 cm−3. The N-type impurity concentration of the first N-type epitaxial silicon layer 12 is about 1E18 cm−3. The N-type impurity concentration of the second N-type epitaxial silicon layer 13 is about 3.5E15 cm−3.
The JBS diode combines a Schottky diode and a PIN diode, which are connected in parallel. The JBS diode is advantageous over a typical PIN diode in that its response time is relatively shorter and its conductive current is relatively higher, because the Schottky diode in the JBS diode has a relatively lower threshold voltage when the JBS diode is forward-biased. The JBS diode also has a relatively lower reverse leakage current, because depletion regions are formed by the P-type grid 14 and the second N-type epitaxial silicon layer 13 in the JBS diode to pinch off the reverse current path when the JBS diode is reverse-biased.
However, the aforementioned prior art JBS diode is inadequate when a further shorter response time, a further lower conductive resistance, and a more precise control of a breakdown voltage are required.
Therefore, to overcome the drawbacks in the prior art, the present invention proposes an JBS diode and manufacturing method thereof, so that the operation speed is increased, the conductive resistance is decreased, and the breakdown voltage is more precisely controlled.